1. Field of the Invention
The present invention pertains to the art of reeling devices and, more particularly, to a compact reeling device for the controlled coiling and uncoiling of a cable from within a housing wherein one end of the cable is fixed to the housing and the other end can be pulled to deploy a desired length of cable.
2. Discussion of the Prior Art
It is widely known in the art to wind and unwind cables from a reeling device. Most often, such a reeling device includes a hub having one end of the cable located at the center of the hub and the remainder of the cable being wound in successive radial layers. In such a reeling device, if one end portion of the cable is fixed relative to the remainder of the cable in order to provide a stationary electrical connection location, some provision must be made to prevent the stationary portion of the cable from twisting, kinking and ultimately failing as the reel is rotated during winding and unwinding of the cable.
In many known reeling devices, such as those commonly used for droplights and vacuum cleaners, slip rings are employed to provide an electrical connection between the stationary and rotatable portions of the cable. Such slip rings can be the source of undesirable electrical noise and intermittent electrical contact. These problems become increasing important when such a reeling device is used in connection with an audio cable. For example, if slip rings are utilized in a microphone cable reeling device wherein a DC power source is superimposed onto an audio signal line of the cable, the slip rings would have to handle both the audio and DC components. This arrangement would generate an undesirable amount of audible brush noise.
In order to overcome the drawbacks associated with using slip rings on reeling devices in certain environments, it has heretobefore been proposed to wind a cable upon both main and auxiliary hubs such that a transitional cable portion would be present between the main cable portion and the fixed cable end. This transitional cable portion would wind and unwind in unison with the main cable portion. Initial designs of this type required the length of the transitional cable portion to be equal to that of the main cable portion. Obviously, such an arrangement disadvantageously results in increased size and cost of the reeling device without the length of the transitional cable portion adding to the effective deployment length of the cable. This problem has been somewhat addressed in the prior art by reducing the hub diameter of the auxiliary reel relative to the main reel. Unfortunately, even varying the diameters of the hubs in this fashion does not significantly reduce the overall bulk of such known reeling devices and certainly does not provide for an extremely compact reeling device.
In reeling devices, it is often desirable to provide a certain degree of tension on the cable while being deployed, while also providing some type of arrangement for maintaining the cable in a desired position once deployed. In the prior art reeling devices, it is common to utilize a mechanical spring which coils as the cable is deployed so as to maintain tension on the cable, as well as a pawl-type locking arrangement for maintaining the cable in a desired deployed position. Such spring/pawl-type reeling devices have various undesirable characteristics. For example, relatively minor tugs on the cable often result in unwanted, sudden and uncontrolled retraction of the cable. Also, locking of the cable is generally limited to particular locations governed by the positioning of the pawl. If too much retraction speed is developed, the pawl may even miss its engaging position and allow further unwanted retraction. Finally, unless controlled in some manner, the retraction speed can become excessive, resulting in a potentially dangerous situation due to whipping of the cable.
Therefore, there exists a need in the art for a compact reeling device which avoids the use of slip rings and which maximizes the length of deployable cable relative to the total length of cable utilized in order to provide for an extremely compact design. In addition, there exists a need for a reeling device wherein the cable can be effectively maintained in a desired location, while ensuring the safe deployment and retraction of the cable.